import type { Link } from './index.mjs';
/**
 * A valued connection between two nodes,
 * being a 3-valued tuple of which the
 * first two elements are nodes and the last element a value
 * @typeparam N - the node type
 * @typeparam V - the value type
 */
export type ValuedLink<N, V> = [N, N, V];
export declare namespace ValuedLink {
    type Target<N, V> = readonly [N, V];
    function fromArgs<N, V>(node1: N, node2: N, value: V): ValuedLink<N, V>;
}
export type ValuedGraphElement<N, V> = [N] | ValuedLink<N, V>;
export declare namespace ValuedGraphElement {
    /**
     * Returns true if the given graph element `e` is a single node.
     * Instructs the compiler that the type is a 1-tuple.
     * @param e - the graph element
     */
    function isSingleNode(e: ValuedGraphElement<any, any>): e is [unknown];
    /**
     * Returns true if the given graph element `e` is a 3-tuple.
     * Instructs the compiler that the type is a 3-tuple.
     * @param e - the graph element
     */
    function isLink(e: ValuedGraphElement<any, any>): e is [unknown, unknown, unknown];
    /**
     * Returns the value of a single node graph element if the given element `e` is a single
     * node, or the given `otherwise` fallback value otherwise.
     * @param e - the graph element
     * @param otherwise - (default: undefined) the fallback value to return
     * if the given element is not a single node
     */
    function getSingleNode<N>(e: ValuedGraphElement<N, any>): N | undefined;
    /**
     * Returns the nodes of the link graph element if the given element `e` is
     * a Link element, or undefined otherwise.
     * @param e - the graph element
     */
    function getLink<N, V>(e: ValuedGraphElement<N, V>): Link<N> | undefined;
    /**
     * Returns the element at the given `key` in the graph element `e`,
     * if the element is a Link element, or returns the given `otherwise` value
     * otherwise.
     * @param e - the graph element
     * @param key - the link key
     * @param otherwise - (default: undefined) the fallback value
     */
    function getLinkElement<N, V, K extends keyof ValuedGraphElement<N, V>>(e: ValuedGraphElement<N, V>, key: K): ValuedLink<N, V>[K] | undefined;
}